Lubricating composition



Patented May 26, 1942 LUBRICATING COMPOSITION Benjamin T. Brooks, New York, N. Y., assignor to American Cyanamid Company, New York, N. Y., 4 a corporation of Maine No Drawing. Original application March 18,

1937, Serial No. 131,628. Divided and this application January 6,1940, Serial No. 312,688

3 Claims. ((31. 252-54) This invention relates to lubricating compositions and particularly to the so-called extreme pressure lubricants.

The present application is a division of my copending application Serial No. 131,628, filed March 18, 1937, Patent No. 2,211,687 issued August 13, 1940.

The standard lubricants for heavy duty service, that is, in internal combustion engines, are mostly hydrocarbon oils. These mineral oils when properly refined are very stable under heat but they are deficient in oiliness and in the strength of the oil'film which is formed between metal surfaces in bearings or at other points where lubrication takes place. Both factors of film strength and oiliness are of great importance in the lubrication of heavy duty bearings such as are encountered in modern internal combustion engines or in gear transmissions with high tooth pressures, for example, hypoid gears. Insufficient film strength will result in metal to metal contact even when an adequate quantity of lubricant is supplied to the bearing and insufficient oiliness will prevent retention of an oil film in the bearingwhen for any reason a lubricant supply becomes insufficient. Both deficient oiliness and deficient film strength permit metal to metal contact which-results in higher wear and also in the rapid development of heat. Modern high speed internal combustion engines operate at so close to the limit of bearing pressures and rubbing speeds that it has been-necessary to change the material used in the bearing, for example to substitute certain bearing metals such as alloys containing silver cadmium and the like, for the standard Babbitt metals. 1

Film strength and oiliness are probably due to 'molecular forces in the oil film, the molecules of which have the property of wetting or adhering to the metal surface. An oil film is retained tenaciously even when the lubricant supply is interrupted for considerable periods of time.

In the past, the problem was first attacked by the incorporation of small amounts of fatty acids into the oil. These compounds did in fact increase the oiliness to some extent, but they did not produce films of high strength and corrosion and other difflculties rendered their use undesirable. Certain esters such as tricresyl and triphenylphosphate and chlorinated esters of fatty acids with mono or dihydric alcohols have been proposed and have achieved some commercial success, notably in the case of tricresylphosphate and chlorinated stearic acid esters. The presence of the acid radical even though combined in ester form was therefore considered to be a desirable component group of such compounds.

.According to the present invention, I have found that ketones obtainable by combining long chain fatty acids such as oleic, stearic, palmitic and the like, or by combining the mixtures of acids obtained from cottonseed oil, lard oil, stearine, fish oil and talloel, and the like, when blended with lubricating oils or greases increase the film strength notably and greatly increase the oiliness of the products. These ketones are very stable under heat and are not corrosive to metals.

The higher molecular unsubstituted ketones have the advantage over other substances used to increase film strength and oiliness in that they do not contain any halogen and therefore cannot decompose to yield hydrochloric acid.

While the halogen free ketones are very eflective and possess the advantage that they contain no constituents which form hydrochloric acid, higher film strengths may be obtained when the products are chlorinated. It is thus possible in the chlorinated products of the present invention chloric acid, HCl from the dichlor product, or

two chlorine atoms from the tetrachlor product. Thepartly dechlorinated products in which the chlorine is adjacent to an'unsaturated or olefin The ketones of the present invention are usable with lubricating oils and greases of the most varying characteristics. The improvementin film strength and particularly in oiliness will, however, in general, differ with different mineral oils. 1

Larger amounts can, of

Thus, for example, with a mineral 'oil stock which has been refined by solvents to such an extent that it has lost most of its oiliness, the addition of the ketones of the present invention will make a much bigger difference than in the case of a mineral oil where the oiliness has not been so completely removed. It should also be understood that the varying purposes for which the lubricating compositions are to be employed determines to a large extent the particular ketone which is to be used. Thus, for example, in the of 300-1bs. at a torque of 75 lbs. The Amsler machine not only measures film strength but gives a rough comparison of oiliness. Tricre'sylphosphate which is a standard addition to lubricants to endow them with extreme pressure characteristics when used in a 1% solution in the same naphthenic base oil as the chlorinated oleone above referred to, gave a film strength of 160 lbs. with a torque of 68. When the amount of tricresylphosphate was increased to 2% the film strength rose to 200 lbs. with an increase of torque of 68. It will be apparent that the chlorinated oleone at a 50% higher load gave somewhat where .the operating temperatures are high and danger of decomposition greater, it is sometimes preferable to use unhalogenated ketones of the present invention which possess high degree of oiliness with lower film strengths.

Other uses may emphasize one or other of the characteristics and in each case the-ketone having the best general characteristics for the particular use should be chosen. It is an advantage of the present invention that a wide choice of ketones halogenated and unhalogenated is available. While the halogenated ketones possess substantially similar properties, whether the halogen is fluorine, chlorine or bromine, the bromine compounds are much more expensive and for the most purposes therefore the chlorine compounds are preferable because of the large saving Example 1 Chlorinated oleone was tested in a 1% solution in a naphthenic base oil on an Amsler machine which has a maximum reading of 300 lbs. The mixture showed a maximum film strength lower torquev than the 2% tricresylphosphate.

Example 2 Oleone was added to a standard mineral lubricating oil for internal combustion engines and tested on an Amsler machine as described in Example 1. Comparison tests with tricresylphosphate showed that oleone was superior to the tricresylphosphate, corresponding to the results obtained with the chlorinated ketone.

It is an advantage of the present invention r' that the addition of the chlorinatedketones does not raise the pour point of the lubricant and most of them lower the pour point, which is, of course, of great advantage as material savings in refining cost can be enjoyed if the added compounds exert suflicient lowering of pour 'point to make the less refined oil meet the normal requirements. Similarly the pour point depressing effect of the compounds of the present invention may be used with oils which already have a very low pour point due to very thorough removing, of wax,

thus producing products which have pour points lower than ordinarily specified which special oils can then be used for extreme cold weather operation.

What I claim is:

1. A lubricating composition comprising a mineral lubricant and a small amount of an oleone.

2. A lubricating composition comprising a mineral lubricant and a small amount of oleone.

3. A lubricating composition comprising a mineral lubricant and a small amount of chlorinated oleone.

BENJAMIN T. BROOKS. 

